Congenital diaphragmatic hernia (CDH) currently carries a mortality in excess of 50 percent. Presently, there exists a need for a reliable procedure for providing the necessary ventilation treatment for patients suffering from CDH.
Recent laboratory and clinical evidence strongly implicates mechanical ventilation (MV) at high peak inspiratory pressure (PIP) in the emergence of respiratory distress syndrome (RDS) in the neonate, child and adult. Recovery from severe lung injury is oftentimes facilitated through the use of extracorporeal membrane oxygenation (ECMO), or extracorporeal carbon dioxide removal (ECCO.sub.2 R), while airway pressures are markedly reduced (lung rest); here, the bulk of CO.sub.2 is removed by the extracorporeal membrane lung (ML), allowing lower tidal volumes (VT), respiratory rates (RR), and PIP. Such lung rest cannot be attained only with the use of an extracorporeal ML.
Conventional mechanical pulmonary ventilation as presently utilized is not considered effective at very high respiratory rates, in part because of unavoidable dead space ventilation.
The effect of the anatomical dead space on CO.sub.2 removal has been well recognized. In the adult and child, MV (or spontaneous breathing) at frequencies in excess of 60 breaths per minute is oftentimes not effective.
Although work has been made in the field of pulmonary ventilation, there remains a need for a method and apparatus which allows for respiratory rates which are well below what is presently considered practical.
U.S. Pat. No. 4,082,093 to Fry et al discloses the use of a compensator valve for use with a ventilation system. A positive end expiratory pressure (PEEP) valve is also furnished to maintain an artificial residual pressure in the lungs. The magnitude of PEEP may be varied from cycle to cycle. The compensator valve functions to hold the lung pressure constant at the end of the expiratory cycle.
U.S. Pat. No. 4,141,356 to Smargiassi discloses a respiratory system with both assisted and spontaneous modes of breathing. A control circuit responds to the patient's breathing pattern to alter the system between the two modes, in accordance with a predetermined pattern. As illustrated in FIG. 1,. the system also includes regulators 10 and 12 which are used to feed a mixture of both air and oxygen.
U.S. Pat. No. 4,202,330 to Jariabka discloses a small tube 13 which is inserted into the trachea for administering oxygen. The tube is connected to a conduit 20 which is connected at 31 to a valving means 30. A second conduit 40 is connected to the inlet 32 of the valve and the other end of the conduit is connected to an oxygen supply 50 which supplies oxygen at a low temperature.
U.S. Pat. No. 4,224,939 to Lang discloses a pulmonary ventilation system in which a respirator feeds air at a controllable pressure, volume, rate, and respiratory frequency to a humidifier. The humidifier is supplied with sterile, heated water. Tube sections 9 and 12 which supply the conditioned air to an endotracheal tube are connected to an inflatable bag 10 by tee 11.
U.S. Pat. No. 4,232,667 to Chalon et al discloses a ventilating system in which both oxygen and an anaesthetic are controllably passed by a flow meter through an inspiratory limb 16 and a small endotracheal tube which is positioned at the approximate level of the carina. An expiratory limb 18 surrounds the inspiratory limb 16. The expiratory limb is connected to an expiratory valve 34. The limbs are provided with spacing ribs 20 to prevent kinking.
U.S. Pat. No. 4,421,113 to Gedeon et al discloses a lung ventilator for carrying out mandatory minute volume (MMV) treatment. The breathing gas source delivers a volume of gas which is at least equal to the maximum volume that may be required. An inspiratory line is connected to the patient's airway for spontaneous breathing. A ventilator is connected to the breathing gas source and is actuated by a signal to deliver a mandatory breath of a predetermined tidal volume to the patient.
U.S. Pat. No. 4,773,411 to Downs discloses a respiratory method and apparatus which establishes a continuous positive airway pressure (CPAP) to enhance functional residual capacity (FRC). Instead of imposing cycles of elevated airway pressure above a CPAP, airway pressure release ventilation (APRV) is utilized to achieve augmentation of alveolar ventilation and carbon dioxide excretion through intermittent cycles of reduced airway pressure below the CPAP pressure level. Breathing gas may be supplied by a variety of devices including a tight fitting tracheal tube.
U.S. Pat. No. 4,593,690 to Sheridan et al discloses an endotracheal tube having an inflatable balloon cuff which is designed so a to be bendable in various directions.
U.S. Pat. No. 4,716,896 to Ackerman discloses an endotracheal tube 40 which is inserted through the mouth of a patient. Within the endotracheal tube is a catheter 10 which delivers a fluid. The catheter has apertures 18a and 18b at its distal end. The catheter may be made of various plastic materials.
U.S. Pat. No. 4,892,095 to Nakhgevany discloses an endotracheal tube having a diffuser 22 at its end.
The present invention is an improvement over existing methods and apparatus utilized in pulmonary ventilation.